The tunable laser system provides a useful research tool to investigate specific laser parameters such as wavelength on lesion shape, ablation depth and thermal tissue damage. It also allows for customization of the characteristics of laser lesions and therefore facilitates the selection of suitable laser parameters for optimized fractional laser treatments. Lasers Surg. Med. 50:961-972, 2018.© 2018 Wiley Periodicals, Inc.

Background and Objectives A recent generation of 5,500 nm wavelength carbon monoxide (CO) lasers could serve as a novel tool for applications in medicine and surgery. At this wavelength, the optical penetration depth is about three times higher than that of the 10,600 nm wavelength carbon dioxide (CO2) laser. As the amount of ablation and coagulation is strongly influenced by the wavelength, we anticipated that CO lasers would provide extended coagulation zones, which could be beneficial for several medical applications, such as tissue tightening effects after laser skin resurfacing. Until now, the 1,940 nm wavelength thulium fiber (Tm:fiber) laser is primarily known as a non‐ablative laser with an optical penetration depth that is eight times higher than that of the CO2 laser. The advantage of lasers with shorter wavelengths is the ability to create smaller spot sizes, which has a determining influence on the ablation outcome. In this study, the ablation and coagulation characteristics of a novel CO laser and a high power Tm:fiber laser were investigated to evaluate their potential application for fractional ablation of the skin. Study Design/Materials and Methods Laser‐tissue exposures were performed using a novel CO laser, a modified, pulse‐width‐modulated CO2 laser, and a Tm:fiber laser. We used discarded ex vivo human skin obtained from abdominoplasty as tissue samples. Similar exposure parameters, such as spot size (108–120 μm), pulse duration (2 milliseconds), and pulse energy (~10–200 mJ) were adjusted for the different laser systems with comparable temporal pulse structures. Laser effects were quantified by histology. Results At radiant exposures 10‐fold higher than the ablation threshold, the CO laser ablation depth was almost two times deeper than that of the CO2 laser. At 40‐fold of the ablation threshold, the CO laser ablation was 47% deeper. The ablation craters produced by the CO laser exhibited about two times larger coagulation zones when compared with the CO2 laser. In contrast, the Tm:fiber laser exhibited superficial ablation craters with massive thermal damage. Conclusions The tissue ablation using the Tm:fiber laser was very superficial in contrast to the CO laser and the CO2 laser. However, higher etch depths should be obtainable when the radiant exposure is increased by using higher pulse energies and/or smaller spot sizes. At radiant exposures normalized to the ablation threshold, the CO laser was capable of generating deeper ablation craters with extended coagulation zones compared with the CO2 laser, which is possibly desirable depending on the clinical goal. The effect of deep ablation combined with additional thermal damage on dermal remodeling needs to be further confirmed with in vivo studies. Lasers Surg. Med. © 2020 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Polymer based thermoelectric pastes have been developed by dispersing metal and metal alloy powders into a polymer binder system. Thermoelectric materials and elements are formed by depositing the pastes into a mold or onto a substrate and subsequently sintering them to form a conductive network with thermoelectric properties. A Seebeck coefficient of 65 μV/°K, and a resistivity of 0.05 Ω-cm have been achieved in the early stage of material development. A novel processing method has also been developed for the fabrication of small size thermoelectric elements and thermoelectric modules with a multitude of thermoelectric couples using these pastes. Thermoelectric elements as small as 250 μm in diameter and 25 μm in thickness have been achieved. Thermoelectric modules with 275 couples/in2have been fabricated using the thermoelectric pastes and the fabrication technique. Further improvement in the material properties and reduction in the sizes of the thermoelectric elements are underway.

A thermal study of an additive technology which is capable of depositing circuit traces directly on a variety of materials, including insulated metal substrates, was done. These metal printed circuit boards are capable of high thermal dissipation of heat originating fi-om high power components as well as fiom dense circuitry. The circuit traces are fabricated using electrically conductive composites based on a transient liquid phase sintering (TLPS) technology. The low processing temperature of these composites allows their use with aluminum substrates and with polymer dielectric materials, resulting in multilayer substrate capabilities.An initial investigation of the thermal advantage of this novel technology over conventional copper traces on FR-4 was performed. Finite element analysis was used to compare the two structures. Along with the computer simulation, thermal dissipation was measured using assembled components as well as temperature mapping using emissivity compensated IR imaging. A serpentine pattem was fabricated using a photoimaging technology which is capable of fine lines and spaces. The test structure was made on a variety of substrates including FR-4, copper-clad FR-4, and aluminum. Different power levels were applied in the serpentine pattern and thermal imaging showed the heat generated on each of these substrates. The benefit of using an insulated metal substrate with no thermally resistive interfaces is readily apparent from the images. A finite element analysis was also performed and compared with the results of the experiment. 0-7803-4486-3/98/$10.00 0 1 998 IEEE

A novel approach to multilayer circuitry based on flexible substrates has been established with prototype manufacture of test vehicles. Comprising the multilayer circuitry are a new conductive bondply and layer pairs (ViaThinTM) based on 50 ym (2 mil) polyimide film. The bondply base film is patterned with 100 ym (4 mil) vias and filled with an organic-metallic composite material (Ormet@) used to interconnect the layer pairs. Circuit traces of 50 pm (2 mil) width, multilayer capture pads of 225 pm (9 mil) diameter, and integrally formed conductive vias of 25 pm (1 mil) diameter comprise the layer pairs in the work described. The bondply vertically interconnects the layer pairs using a lamination process common in the printed circuit board industry. Eight-layer circuits have been fabricated, employing four circuit layer pairs and three bondply interlayers. The multilayer technology presented was developed within the DARPA-funded MCM-L consortium.

The immobilisation of DNA probe on gold electrode surface with the optimal concentration is very important to develop of the DNA biosensors. In this study, we conducted an experiment that determined the optimal concentration of the probe attached the electrodes for the maximum hybridization efficiency. We have used a method that control the surface density of DNA probe by annealing probe modified by thiol and mercaptohexanol. Based on the linear relationship between the mol ratio and density probe, we control probe concentration in the sensor fabricating process as well as the molecular density of DNA probes on the electrode surface. The result of probe concentration 500 nM is optimal for hybidization with DNA target.

The optimization of DNA probe immobilisation on gold electrode surface is very important to develop DNA biosensors. In this study, we conducted an experiment to determine the optimal concentration of probe attached on the electrodes and probe immobilization agent (mercaptohexanol) for maximum hybridization efficacy. We have used a method to control the surface density of DNA probe by annealing probe modified by thiol and mercaptohexanol. With linear relationship between molar ratio and surface density of probe, by controlling probe concentration in sensor fabricating process, we can determine the molecular density of DNA probes on electrode surface. The results show that probe concentration 500 nM and 1.5 mM mercaptohaxenol are optimal for hybidization with DNA target.

In this paper, we study the electrochemical properties of selfassembling monolayers (SAM) created by the adsorption and desorption of the alkanethiol at the gold nanowires (AuNW) electrode surface by using the CV method. The analysis results show that the effectiveness of the desorption process reached over 90 %. The adoption of a negative voltage caused SAM desorption which resulted in the separation of SAM from the electrode. Our purpose is to reuse gold electrodes after they have been functionalized by SAM. Besides, results of this study also help to eliminate the electrochemical methods that make SAM eluted and therefore protect samples more effectively in the survey process.